This invention relates to automatic wire bonding machines for use in ball bonding. One known type of such machine comprises a flame-off electrode which is used to form a ball on the free end of a bonding wire fed through a capillary of a bond head, which electrode is lifted away from its ball forming or operating position, before the bond head is lowered into position for bonding.
Generally in a wire bonding machine of this type, the flame-off electrode is lifted away from its operating position by means of a solenoid, before the bond head is lowered into its bonding position. There are two principle disadvantages in this system involving the use of a solenoid. The first is that the speed of operation of the solenoid is slow, which limits the overall bonding time, and the machine throughput. The second disadvantage is that synchronisation between movement of the flame-off electrode and movement of the bond head can also cause problems, leading to a further limitation on the speed of operation of the machine. In order to avoid damage to either the flame-off electrode, or the capillary of the bond head, through which the wire is supplied, an additional margin for safety has to be built into the operation of the machine to attempt to ensure that contact between these two components is avoided.